This application claims the priority of Korean Patent Application No. 2002-19475, filed Apr. 10, 2002, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein in its entirety by reference.
1. Field of the Invention
Methods and apparatuses consistent with the present invention relate to a method and apparatus for driving a belt in a belt system, and more particularly, to a method and apparatus for driving a belt, in which an amount of initial weaving of a belt is reduced when the belt is driven.
2. Description of the Related Art
In general, a belt is used as a photoreceptor or transfer medium in electrophotographic image forming apparatuses such as printers, copiers, and facsimiles. This is because a belt requires a small volume and the need for spatial utilities is high. In particular, a belt is mainly used as a photoreceptor or transfer medium in multicolor image forming apparatuses. Specifically, when images of a multicolor toner are overlapped on a photoreceptor, a belt is mainly used as the photoreceptor. In addition, when images of multicolor toner are overlapped on a transfer medium, a belt is mainly used as the transfer medium. Also, when images of toner are transferred onto a recording medium such as paper, and the images are overlapped, a belt is mainly used as an apparatus for moving the recording medium. Also, a belt is used in an oil supplying apparatus of a fusing apparatus or a cleaning apparatus in electrophotographic image forming apparatuses. In the case of liquid electrophotographic image forming apparatuses, a belt is used in a drying apparatus.
In systems using a belt, weaving of a belt typically occurs when the belt is driven. In particular, weaving of a belt used as a photoreceptor or transfer medium in electrophotographic image forming apparatuses, such as printers, copiers, and facsimiles, is the chief factor of mis-registration by which images in a main scanning direction are not aligned to each other.
Weaving of the belt causes mis-registration in which the starting positions of lines are not aligned within one page. In addition, when color images are formed, color mis-registration in which color dots are not accurately overlapped with each other, can occur. Thus, in image forming apparatuses using a belt as a photoreceptor or transfer medium, the position of the belt in a main scanning direction (direction of a width) needs to be controlled so as to prevent weaving of the belt. This position control is referred to as steering control.
A home sensor that detects a home position is provided in belt steering systems, and is the basis of an operation of a steering roller that moves the belt in the main scanning direction.
FIG. 1 is a flowchart illustrating a conventional method of searching for a home of a steering roller. Referring to FIG. 1, in order to search for the home of the steering roller, the belt rotates and is driven, and a steering motor is driven such that the position of the steering roller is adjusted (S1)(S2). The position of the home of the steering roller is searched for using the home sensor while the steering motor is continuously driven (S3). If the home position of the steering roller is found, the operation of the steering motor stops such that a process of searching for the home of the steering roller stops (S4)(S5).
In the above-mentioned conventional method, the position of the steering roller is changed by driving the steering motor when the belt is driven, and thus the position of the belt, which rotates and is driven on the steering roller, is greatly changed. Thus, as shown in FIG. 2, when the steering motor for searching for the position of the home sensor is driven, the amount of initial weaving of the belt caused by the change of the position of the belt, which is in turn caused by movement of the steering roller, is increased. Thus, a great amount of time is needed to obtain registered images while steering control is performed.